The Chemical Behavior of Fluorine 18 Produced by the O16(H3,n) Nuclear Reaction

Abstract

F/sup 18/ atoms produced by the Li/sup 6/(n, alpha )H/sup 3/, O/sup 16/ (H/sup 3/ ,n)F/dup 18/ nuclear reactions were found to substitute hydrogen on organlc molecules. The extent of labeling of a given organic molecule was found to be proportional to the number of hydrogens per molecule. In solid lithium salts, irradiated by slow neutrons, the yield of organically bound F/sup 18/ was 0.6 to 1.0% per aliphatic hydrogen, as compared to 0.3 to 0.6% per aromatic hydrogen. Compounds were also labeled in solutions and the yleld was dependent on the concentration of the solute. The yield of labeling of aliphatic solutes was higher than that of aromatic. The addition of aromatic compounds to an aliphatic solvent diminished the labeling yield of the solvent, however no appreciable labeling of the aromatic solute was observed. Aliphatic solutes, on the other hand, did not affect the yield of labeling of aliphatic solvents. Formic acid and nitrite ions were found to diminish considerably the yield of labeling in aqueous or alcoholic solutions. The results suggest that the active chemical species in the fluorine labeling reactions are non-excited fluorine atoms. Interactions with electron donors are of primary importance in the behavior of fluorinemore » atoms in organic media.« less